Effect　of　cooling　structure　on　the　steam　cooling　performance　on　the　intermediate　pressure　turbine　stages　for　ultra-supercritical　steam　turbine　was　numerically　investigated　by　flow　field　calculation　with　conjugated　heat　transfer　method.　The　computational　domain　includes　the　blade,　blade　root　and　wheel　disc　of　the　first　two　intermediate　pressure　turbine　stages.　The　temperature　fields　and　cooling　effectiveness　of　the　rotating　components　of　the　first　two　intermediate　pressure　turbine　stages　were　compared　between　the　original　design　and　three　different　cooling　hole　designs.　The　results　show　that　the　four　cooling　structural　designs　are　able　to　lower　the　temperature　of　the　blade,　blade　root　and　wheel　disc　of　the　first　stage.　The　reduction　of　the　area　of　the　cooling　hole　at　the　bottom　of　the　blade　root　effectively　increases　the　regions　of　the　blade　root　and　wheel　disc　covered　by　the　cooling　steam　to　improve　the　steam　cooling　effectiveness.　The　cooling　structure　with　sealed　cooling　hole　completely　prevents　high　temperature　main　stream　to　ingress　into　the　disc　cavity.　The　optimum　steam　cooling　effectiveness　for　the　the　blade　root　and　wheel　disc　using　this　cooling　hole　structure　is　obtained.　©,　2015,　Xi＇an　Jiaotong　University.　All　right　reserved.